Many methods and products have been developed, for example, to deter counterfeiting of valuable documents or financial instruments such as currency, so that unauthorized copies attempted to be made from those documents can be readily distinguished from the originals. Most of these methods and product involve preparing an original document by printing or lithography on high quality media such as silk, rice paper, and high contact rag paper. The printing of original documents may be done either in black-and-white (B&W) or in color, and if in color, either in spot color, colored backgrounds and/or multicolor printing. In the case of color, the tendency has been in the direction of using multiple colors for original documents for aesthetic value, for ease of recognition, and originally for protection from copying by conventional means. The common printing processes of valuable originals, whether in B&W or in color, are intaglio and gravure, among others. These and the other processes mentioned in this application are very well known in the art and will not be discussed in great detail.
Most of the useful examples in the prior art to deter counterfeiting and the like are intended to ensure that copies are produced either with a distinct moiré distortion or with a “latent image” indicia bearing a warning message which is invisible or nearly invisible to the naked eye on the original document. The term “latent image” is used here not in the photographic sense of an unseen image to be developed after processing by chemical reaction, but to indicate indicia that are printed on originals so as to be nearly invisible to the naked eye.
These and other developments in the prior art for purposes of providing document protection are disclosed in the patent literature, as for example, in U.S. Pat. No. 5,018,767 issued May 28, 1991; U.S. Pat. No. 5,193,853 issued Mar. 16, 1993; and U.S. Pat. No. 3,675,948 issued Jul. 11, 1972; and U.S. Pat. No. 4,143,967 issued Mar. 13, 1979, all to Ralph C. Wicker; in U.S. Pat. No. 4,227,720 issued Oct. 14, 1980 and U.S. Pat. No. 4,310,180 issued Jan. 12, 1982 both to William H. Mowry, et al, as well as U.S. Pat. No. 5,149,140 issued Sep. 22, 1992 to Mowry et al; and in U.S. Pat. No. 5,487,567 issued Jan. 30, 1996 to John R. Volpe. All of these patents disclose various means for providing methods and products to enable copies of documents to be distinguished from the originals, as for example, by a “large dot-small dot pattern”, a “close line-spaced pattern”, and images or indicia which are screen printed at minutely varied spaces and/or angles on the originals and are intended to produce a highly visible moiré pattern effect on the unauthorized copies. In this specification, the words “print”, “printed” and “printing” are used to refer to the making of an original document by transferring an image using hand drawn press prints, painting, or digitally transferred through analog and digital photography and in addition, through video, Digital Versatile Disc (DVD) and Compact Disc (CD) technology. The words “copy” and “copying” to refer to making copies from an original.
A significant commercial use of security images is in commercial paper, such as personal checks. Personal checks conventionally originate from a particular banking institution and often bear one or more security images, either latent images or non-latent images, associated with the originating banking institution. When a personal check is presented to another banking institution for payment of a debt, the paper copy of the check is typically returned to the originating bank, which may use the security images to verify that the check is a valid check. However, under a new U.S. Federal Reserve regulation called “Check 21”, effective in October 2004, banks at which checks are deposited are no longer be required to return the original paper check to the bank on which the check has been drawn. Instead, the originating bank receives only electronic images or scans of its checks from the banks at which the checks have been deposited. This regulation is expected to allow a considerable savings in transaction costs for the banking industry by avoiding the need to sort and mail the paper checks to their originating bank.
However, security images contained on conventional commercial paper, such as original checks, do not survive the scanning process, i.e. they are not reproduced in the scanned copy of the original check. Accordingly, the originating bank cannot effectively verify if the check presented to the depositing bank is a valid check. The difficulty in verifying the authenticity of a presented check raises significant concerns over the potential for increased check fraud once the new “Check 21” regulation goes into effect. While Check 21 significantly speeds the handling and collection of checks, the potential for enormous unprosecutable check fraud losses is nearly certain, as the conversion process destroys the evidence of fraud in most cases. To counter such fraud in a cost-effective manner, it is desirable to have image-survivable security technology as a feature or features that can be authenticated using images already captured as a normal part of the sorting process. Such a solution would require no additional expenses or modifications to the different hardware platforms already in place.
However, the current security images on conventional commercial documents do not survive the scanning process of the conventional scanners used in the banking industry. The banking industry uses relatively high speed, low-resolution scanners. A digital bit map image of the commercial paper is typically obtained and stored. The scanner is unable to distinguish the security image and hence does not reproduce the security image in the digital bit map image of the commercial paper.
Accordingly, there is a need to provide a security feature that serves to distinguish a copy of a document from an original and is able to survive the scanning process on the current generation of check processing equipment used by the banking industry.
Another significant commercial use of security images is in coupons and gift certificates issued by retailers, to prevent fraudulent copying. Currently, such documents must be created by a specialist using printing or lithography and/or high-quality paper, thereby raising the cost of the documents. There exists a need for the ability to inexpensively create original documents having security features on a digital printer using plain paper.
Another significant commercial use of documents having security images is in currency, traveler's checks, and laminate (films). To avoid counterfeiting and to provide fast and accurate authentication of such documents, ultraviolet or infrared hidden security images, using anywhere between one and four or more colors have been employed. However, a need exists for hidden images that provide greater security than those currently available.